Automatic primer for internal combustion engines



1 J. w. FlTZ GERALD 2,063,037

AUTOMATIC PRIMER FOR INTERNAL COMBUSTION ENGINES Filed March 12, 1934 2Sheets-Sheet 1 mmM z JZ/fin MEXIZEFFE/H Dec. 8, 1936. J. w. FlTZ GERALD2,063,087

\ AUTOMATIC PRIMER FOR INTERNAL COMBUSTION ENGINES Filed'March 12, 19542 Sheets-Sheet 2 2 IMWM Patented Dec. 8, 1936 UNITED STATES PATENTOFFICE AUTOMATIC PRIMER FOR INTERNAL COMBUSTION ENGINES ApplicationMarch 12, 1934, Serial No. 715,133

9 Claims.

This invention relates to new and useful improvements in primers forinternal combustion engines and has as an object to provide anautomaticthermally controlled priming device par- 5' ticularly adaptablefor automotive vehicle engines. Another object of this invention is toprovide an automatic priming device wherein a valve biasedto openposition and closed by engine suc- 10 tion, has its opening and closingmovements directly controlled by temperature actuated means.

And a further object of this invention is to provide an automaticpriming device of the character described, which is extremely simple inconll;v struction and positive in operation.

With the above and other objects in view which will appear as thedescription proceeds, my invention resides in the novel construction,combinatio n and arrangement of parts substantially go as hereinafterdescribed and more particularly defined by the appended claims, it beingunderstood that such changes in the precise embodiment of thehereindisclosed invention may be made as come within the scope of theclaims. 5 In the accompanying drawings, I have illustrated one completeexample of the physical embodiment of my invention constructed accordingto the best mode I have so far devised for the practical application ofthe principles thereof, and 30 in which:

Figure 1 illustrates part of the carburetor and manifolds of an internalcombustion engine showing the application of this invention thereto;

Figure 2 is an enlarged side view of the primer 35 showing the positionof the thermal control members at cold temperatures;

Figure 3 is a longitudinal section view taken through Figure 2 on theplane of the line 3-3;

Figure 4 is a cross section view taken through 40 Figure 3 on the planeof the line |-4; and

Figure 5 is a side view similar to ,Figure 2, showing the thermalcontrol membersin their opposite positions towards which they move inresponse to higher temperatures;

45 Referring now more particularly to the ac.- companying drawings inwhich like numerals indicate like parts throughout the several views,

the numeral 5 designates the carburetor of an internal combustion enginesupplied with fuel erally by the numeral 1, which, as is customary, hasa portion thereof juxtapose the exhaust manifold 8..

In accordance with this invention, an auby a supply line 6. The outletof the carburetor connects with an intake manifold indicated gentoinaticpriming device, indicated generally by the numeral 9, and mounted in theregion of the exhaust manifold, provides a controlled communicationbetween the supply line 6, through ducts l and H directly to' the intakemanifold, as clearly shown in Figure l.

When the engine is cold, as during the starting cycle, the primingdevice permits a direct communication between the supply line 6 and theintake manifold so that fuel may be drawn di- 10 rectly into themanifold. Upon increase in suction in the intake manifold produced bythe engine in operation, the communication between the supply line 6 andthe manifold is closed a degree dependent upon the temperature of the 16engine.

To this end, the priming device comprises a body l2 having an inlet l4and an outlet I6 with which the ducts l0 and II respectively, connect.Leading from the inlet I4 is a small diameter 20 bore l3. At a medialpoint in the length of the body I2, the bore I3 is abruptly increased indiameter to afford a larger diameter bore IS with which the outlet l6communicates through a lateral bore IS. The outer end of the bore I5 isfurther'abruptly enlarged to provide a comparatively large diameter boreH, which opens to the adjacentpnd of the body to be closed by a head l8.

The'bor'es l3, l5 and I6 provide a fuel passage through the body and thebore I1 affords a cylinder within which a piston I9 is slidablydisposed.

The piston I9 is fixed to the stem 20 of a needle valve 2|, arrangedwith its point projecting into the bore l3 to completely close the fuelpassage.

The valve stem 20 is slidably passed through the head I8 to projecttherebeyond for a purpose to be hereinafter described.

Encircling the stem between the piston and the bottom of the bore I1 isa' compression spring 4 22, which yieldably tends to hold the needlevalve open. The action of the spring is opposed by the suction of theengine created within the intake manifold and acting upon, the pistonl9. To insure communication between the outlet port I6 and the bore orcylinder H, the inner end of the valve stem is polygonal-in crosssection, as clearly shown in Figure 4, and to allow free response on thepart of the piston to the effects of suction, the head l8 has aplurality of air bleeds 23.

Hence, it will be seen that when the engine is stationary or when itisoperating under such conditions that the suction created thereby isinsuflicient to overcome the force of the spring 22,

the need e valve 2| will be held open, permitting fuel to be drawndirectly from the supply line 8 into the intake manifold, ,but when theeifect of suction is increased, its-action upon the piston l9 overcomesthe spring 22 and closes the needle valve 2| to close the fuel passageand shut off the admission of fuel to the intake manifold.

The admission of the priming fuel to the engine isffurther controlled bymeans responsive to variations in the ambient temperature. This meanscomprises two thermal elements 24 and 25, both preferably formed-ofstrips of bi-metal anchored at one end to the body I 2 as at 26 and 21respectively, to overlie opposite sides thereof with their free endsprojecting'beyond the adjacent end of the body.

Each of the thermal elements .at its free end carries an adjustablestop, the stop 28, which is carried by the member 24 having a roundednose 29 and the stop 30, which is carried by the member having a squareinner end 3|. These .stops are directed inwardly toward each other toengage a disc 32, adjustably'flxed on the extended end of the valvestem. The inner face of this disc is-stepped as at 33, and the outerface thereof is inclined to provide a substantially conical surface 34.

When the engine'is 061d, as during an mamaw starting cycle, the thermalelements 24 and 25 are flexed to their positions illustrated in Figure2. At such prevailing temperatures, the member 24 holds the stop 23entirely away from the disc 32, but the member 25 holds its stop towardthe axis of the valve stem engaging its inner end 3| with the steppedinner face 33 of the disc, it being understood that the valve stem'isheld outwardly under such conditions by the spring 22. Consequently, thevalve-will be held against closing in response to the efl'ect of suctionon the piston l9 until the. ambient temperature has raised willcientlyto move the thermal-control element 25 outwardly to disengage the end 3|of its stop 3.

from the steps of the disc 32 with which it is engaged.

close the needle valve thus progresses step by step as determined by theresponse of the thermal .elemeat 25 to the rising ambient temperature.Concomitantly with the movement of the member 25 to carry its stop awayfrom the disc 32, the thermal element 24 moves its stop 23 inwardly todle valve is precluded even though thesuction of the engine may drop toan extent which normally 'would permit the spring 22 to function.Obviously, as the ambient temperature. drops, the. reverse procedure onthe part of the thermal control elements 24 and 25 takes place. 1

As the free end of the control element 24 moves outwardly,'can'y ing itsstop 23 toward the outer periphery of the conical surface 34 of the disc32, the spring 22 forces the valve 'stem 20 outwardly to maintain theconical surface 34 in engagement with the rounded nose 23 of the stop28. During this time, the thermal control element The inward movement ofthe valve stem to The engagement'of the stop with the stepped portion ofthe member 32, however, does not affect the outward projection of thevalve stem by its spring 22 as the frictional engagement between the endof the stop and the stepped portion of the disc is insuiiicient tooppose the action of the spring 22. Consequently, the valve stem movesoutwardly at a rate determined by the outward flexure of the controlelement 24', until the element 24 is moved a distance suilicient todisengage its stop 23 from the disc, whereupon the spring 22 is free tomove the valve stem to its outermost position at which the needle valve2| is entirely open.

It is to be understood that while in Figure 1 the exhaust manifold, itmay be located adjacent any other part of the engine which is subject tovariation in temperature as is required for proper operation of thedevice.

valve to openposition, a valve stem for the valve having. a partprojecting to the exterior of the body, engine suction operated meanswithin the body and connected with said valve stem to claw the valve,and temperature responsive means mounted on the exterior of the body andoperably associated with the valve stem to regulate the opening vof thevalve by its yieldable urging means in accordance with temperaturechanges in the region inwhich said body a m'olmted and to preventclosing of the valve'by engine suction until a predetermined ambienttemperature has been reachedat said region. Y

2. In an automatic priming device of the character described comprisinga body having a fuel passage therethrough, a valve operable within thebody to close said passage and to control the admission of fuel into theengine, a valve stem movable with the valve, a spring yieldingly urgingthe valve open," a piston connected to the stem and operating in' a..cylinder formed in the body, said cylinder being communicated with a.source of engine suction so that the piston is ve to engine suction; toclose the valve against the action of the spring, and temperatureactuated means operable on the stem in accordance with priming device isshown in the region of the temperature variations of the engine partsadjacent the device for controlling the opening of the valve-byits-yieldable urging means and for preventing the closing of the valveby the response ofsaid piston to engine suction until a predeterminedambient temperature has been reached. r

3. An automatic priming device of the character. described including avalve for controlling the admission'of fuel to the engine, a spring toyieldably urge the valve open, engine suction responsive means to closethe valve against the changes thereat, and a member connected with 7aoeaoar the valve and engageable by parts carried by said thermalelements.

4. An automatic priming device of the char acter described comprising, avalve to control the admission of fuel to an engine, a spring toyieldably urge the valve open, engine suction actuated means to closethe valve against the action of said means,'and temperature actuatedmeans to control the closing and opening of the valve comprising amember movable with the valve and having surfaces at varying distancesfrom the valve, and thermal elements having, stops engageable with saidsurfaces and movable in' opposite directions across said surfaces inresponse to temperature changes thereat.

5. An automatic priming device of the character described comprising avalve to control the admission of fuel to an engine, means to yieldablyurge the valve open, means responsive to a condition of the engine toclose the valve, and temperature actuated means to control the opening.

and closing of the valve comprising a member connected with -the valveto be movable therewith and opposite surfaces each of which has portionsat different distances from the valve, and thermal elements having stopsto engagesaid surfaces, engagement between the stop of one thermalelement and its respective surface of said member limiting the movementof said member in one direction and engagement between the stop of theother thermal element and its respective surface of said member limitingthe movement of said member in the opposite direction so that theopening and closing movements of the valve are limited to distancesdetermined by the degree the spring, and temperature actuated means to.control the closing and opening of the .valve comprising, a membermovable with the valve andhaving opposite surfaces with portions atpro-"' gressively different distances from the valve, bi-

metallic strips anchored at one end with their free ends disposedadjacent said "last designated member and at opposite sides thereof,stops carried by thefree ends of said bi-metallic strips to engage theopposite surfaces of said'member to limit the mdv'ement of said-memberand consequently the valve to distances determined by the amount ofengagement of said stops with the sur-' faces, and said bi-metallicstrips moving in opposite directions in response to temperature changesthereatr 77,. An automatic priming device of the charac-' ter describedcomprising a body having a fuel passage connectable with a source offuel and a source of engine suction and having a cylinder bore incommunication with said passage, a valve said strip to close saidpassage andcontrol the admission of fuel to the engine, a stem on thevalve extending through the cylinder bore to the exterior of the body, aspring to yieldably urge the valve open, a piston on said'stem operatingin said cylinder bore and responsive to engine suction to close thevalve, a member mounted on said stem exteriorly of the body and havingopposite faces with portions 'at different distances from the valve, andtemperature actuated means having 10 stops to engage said surfaceportions of said member to control the opening and closing of the valvein accordance with changes in temperature at said temperature responsivemeans.

8. An automatic priming device of the charac- 15 terdescribed comprisinga body having a fuel passage connectable witha source of fuel and asource of engine suction and having a cylinder bore in communicationwith said passage, a valve to close said passage and control theadmission 20 of fuel to the engine, a stem on the valve extendingthrough the cylinder bore to the exterior of the body, a spring toyieldably urge the valve open, a piston on said stem' operating in said,cylinder bore-and responsive to engine suction to 25 close the'valve, amember mounted on said stem exte'riorly of the body and having oppositefaces with portions at different distances from the valve, a pair ofbi-metallic strips anchored at one end to said body with their free, endportions dis- 30 posed at opposite sides of said member, and stops valvein accordance with temperature conditions 35 at said bi-metallic strips.

9. An automatic priming device of the character described comprising abody having a fuel passage therethrough connectable with a fuel supplyand a part of an engine subject to engine 40 suction and having acylinder bore in communi- V cation with said passage, a valve in thebody to close said passage and control the admission of fuel to saidengine part, a spring yieldably urging the valve open, a stem on thevalve projecting to 45 the exterior of said body and passing throughsaid cylinder bore, a piston on said stem operat-l ing in said cylinderand responsive to engine suction to close the valve, a member on saidstem exteriorly of the body and having one face'thereof stepped and itsother face inclined, a'pair-of bi metallic strips anchored to said'bodywith theirfree ends arranged at opposite sides 'of id disc, and stopscarried by the free end no tions of said strips, one of said stops beingengageable 55 with the stepped surface of the disc to limit the closingmovement of the valve in accordance with flexure of'said strip inresponse to temperature risesand' the stop of the other bi-metallicstrip being engageable with the inclinedsurface of the disc to, limitthe opening movement of the valve. to distances determined by thetemperature at JOHN w. m GERALD.

